Grease gun



Sept. 26, 1939. J. KRANNAK GREASE GUN Filed Aug. 15,1936 2 Sheets-Sheet 2' FAN/VAX trated in the drawings.

Patented Sept. 26, 1939 GREASE GUN Steven J. Krannalr, Minneapolis, Minn., assignor to Min-A-Max 00., Minneapolis, Minn, a. corporation of Minnesota Application August 15, 1936, Serial No. 96,212

12 Claims.

- My present invention provides a simple and highly eillcient grease gun and a grease-containing cartridge therefor, in an arrangement wherein the contents of the cartridge may be ejected under the action'of a piston or like permanent element of the grease gun proper.

The grease-containing cartridge is preferably in the form of a cylindrical, thin sheet metal shell, but may be made of any other suitable material. The cartridge at one end has a large removable head, and at its other end has a small axially discharged passage normally closed by-a removable plug orsmall cap. The grease gun has 2. containing chamber or barrel, preferably of cylindrical form, provided at one end with a grease discharge nipple, and equipped at its other end with an ejecting piston and cooperating actuating ineans. The axial discharge nipple of the barrel is lnsertable into the axial discharge passage of the cartridge; and the eect ing piston, which acts as a follower, is insertable into the large open end of the cartridge, which later is held and centered by a presser device, so that the piston will enter the said cartridge, and the discharge passageat the other end of the cartridge is tightly seated onto the discharge nipple of th barrel head.

The invention also involves novel devices and features, preferred forms of which are illus- In the drawings, which illustrate two embodiments of the invention, like characters indicate like parts throughout the several views.

Referring to the drawings: 7

Fig. 1 is an axial section showing the invention embodied in a grease gun in which a high pressure or final grease discharge ejector is operated by air pressure;

Fig. 2 is an axial section showing the cartridge in closed condition; I

Fig. 3 is an axial section showing the invention embodied in a grease gun in which the high pressure ejector is hand operated;

Fig. 4 is a transversesection taken on the line l4 of Fig. 3; and

Fig. 5 is'a transverse section taken on the line 5-5 01 Fig. 3

The cartridge which, as above stated, may be of any suitable material, is preferably made up of a thin sheet metal cylinder 6, provided at one end with a large removable head I and provided at its other end with a permanent head 8 having an axial passage 9 normally closed by a removable plug or cap Ill. The fixed head 8 is clinched to the delivery end of the cartridge,

and the plug I is frictionally but securely forced into the axial passage 9. At its other end the cartridge shell 6, for an important purpose which will hereinafter appear, is slightly enlarged or increased in diameter at Ii. The' large head 1 is frictionally but securely pressed into the enlarged end portion ll so that, when the head 1 and plug Ill are applied, the cartridge will be sealed liquid-tightand adapted to contain lubricating grease or oil. This cartridge shell with 10 grease or lubricating material is adapted to be shipped and handled like other canned materials, and the cartridge is ready at any time to be quickly inserted into the grease gun.

The grease gun, illustrated in Fig. l,'is of the pneumatic type, and for containing the cartridge it is provided with a barrel or container i2 of very light metal. At its delivery end the barrel I2, by screw threaded engagement or otherwise, is detachably secured with a fluid-tight joint to a head i 3; and at its other end said barrel by 1 like means is detachably secured to a head it.

The head i3 has an axial passage it formed through a tapered nipple it that projects into the barrel, when the latter is applied to the head It. The head it is provided with the hub into which by threaded engagement is screwed the shank of an operating head or handle ll connected as a permanent part of the head it and adapted to be inserted into the cartridge, as

hereinafter described, as a piston head It which, as shown and preferred, comprises disc-like piston plates l8 and lil and clamping discs I9. The discs I 9 are shown as screw-threaded onto a hub 26 and securely clamp the -disc-like plates I8 and l8 together. These plates ifi and l8 are of a pliable material, such as leather, rubber,

or composition material. The hub 20 as shown,

is a hollow structure and contains a quite light 40 coil spring 26.

The operating head I! is connected to the piston head by means of a. telescopically extensible piston stem, as shown, made up of three elements 22, 23 and 24. The outer member 22 is a tubular structure which, at its outer end, is

rigidly secured to the head I? and at its inner end has an inturned flange 22 The member 23 is of tubular form and of such diameter as to pass through the opening of the flange 22, but at its outer end is provided with an outturned flange 23 that will engage said flange 22. The member 24 is a rod telescoped into the member 23 and provided at its outer end with a, collar 24 that is engageable with an inturned flange 23 on the inner end of member 23. The inner end of rod 24 is extended with a loose joint which will pass air through the outer end of the hub 20, and at its extreme inner end said membe1 24 is provided with a collar 24 that engages the outer end of spring 2|. Keyed, pinned,

or otherwise rigidly secured on the rod 24 is a valve-acting collar or flange 25 which,- when pressed against the adjacent end of hub 20, closes the air passage between said rod or member 24 and the contracted end of the hub 20. The important purpose of this structure will appear in the description of the operation.

Working slidably within the barrel I2 is an annular pressure collar 26, the inner edge of which is inwardly beveled for engagement with the large adjacent end of the cartridge shell This 001- lar 26 is subject to a heavy coiled spring 2'! cornpressed between the shoulder end thereof and the head l4. Whenthe head I and the plugs I0 have been removed and the cartridge is placed in the barrel, as shown'in Fig. l, the rim of the axial opening |6 will be tightly pressed with the fluid-tight joint on the tapered discharge nipple l5, under the action of the spring 21. The manner in which the cartridge-will be opened up and applied, as shown in Fig. 1,. will be fully described.

One or more cartridge shell distorting dogs 28 are intermediately pivoted to the rear or outer piston head plate l9, and subject to the action of the projecting flange of the valve 25, perform the function that will more fully appear in the description of the operation.

The barrel head l3 in the structure illustrated is shown as cast or formed integral with the shell or casing 29 of a difierential high compression encased ejector. This casing 29 is formed with a relatively very large cylinder 30 and with a relatively very small cylinder discharge passage 3|. Working in the large cylinder 30 is a large piston head 32 that carries a plunger 33 that fits the small cylinder or discharge passage 3| and acts as an ejecting piston or plunger. The inner end of each cylinder or discharge passage 3| is in communication with the grease passage |5 of the head with a handle 39 normally closed by a choke valve 36 subject to a clamping screw 31 The outer end of large cylinder 30 isclosed by I a head 38 which, as shown, is formed integral Compressed air will be delivered to the cylinder 30 and against the piston head 32 through air conduits 40 and 4|. Normally, communication between air conduits 40 and 4,| is shut off by spring pressed valve-42 which has an exposed finger or thumb piece 43 adapted to be pressed to open said valve.

Air conduit 4| is adapted to be connected to the barrel l2 through a branch air conduit 44 in which is a lightly spring pressed check valve 45-.

Figs. 3, 4 and 5 illustrate the invention embodied in a grease gun in which the high compression or final grease ejector is a hand operated device. In these views, the same cartridge illustrated in Figs. 1 and 2 is employed, and hence,.' the parts thereof are indicated by the same characters. A great deal of the mechanism of the barrel and interior mechanism of the grease gun 5 are herein identical or substantially the same as corresponding parts previously described, and hence, these corresponding similar parts are indicated by the same characters with the prime marks. I

In this structure, the rod or stein section 24 is screwed'or otherwise rigidly applied in the neck 46 of a large sleeve 41 that surrounds but is spaced from the outer stem section 22'. The rod or stem section 22' in this structure is provided with a supplemental section 48 that is screwed into the neck 46 and has a flanged front end that works with clearance in the cavity of the hub'20'. The neck 46 has a flanged end 49 between which the inner end of the sleeve 41 works with clearance. The said flanged end 49 is normally pressed against the piston head and closes the passage around the stem extension 48, under the action of a coiled spring 5|) contained within said sleeve and reacting against the sleeve and the head H. The outer end' of sleeve 50 is beveled, and adjacent thereto is provided with a lock groove 5|. Numeral 52 indicates a small latch or look lever mounted on a stud 53 projecting from the head M. This latch lever is subject to a tension spring that causes the inner end of said lock lever to engage the lock groove 5| when the latter is aligned therewith.

The outer end of the outer stem section 24 is screwed in or otherwise rigidly secured to a shank of an operating handle H. The shank of this handle I1 is telescoped into a projecting neck 55 of a head l4 and is quite securely but movably latched to said neck, under the action of a spring pressed latch plunger 58 mounted in said shank and engageable with an annular groove 51 of said neck.

In this modified structure, the head 13' is provided with a tapered nipple l6 onto which the small opening in the end of the cartridge head 8 is adapted to be pressed, under the action of the spring pressed 'collar 26'. The passage nipple I6 is connected by a conduit |5' to the bore or barrel 58 of an ejecting grease gun 53 which, as shown, is cast or made integral with or otherwise rigidly secured to the head l3 and is formed with an enlarged extension 60. An ejecting piston in the form of a rod or plunger 6| works in the barr 58 and, as shown, is provided at its extended end with an operating knob 62, and within the enlarged extension 6|! with a. stop collar 6-3.

Operation of the structure illustrated inFigs. 1 and 2 filled with grease so that it is an easy matter 7 to press the piston slightly into the normal diameter of the cartridge shell. Expanded end of the cartridge shell assists in effecting the initial entry of the piston into the shell.

When the pistonhas thus been initially entered 7 open check valve 34.

into the cartridge shell, it is turned open end up, and the plug II is then removed. Next the head I: with the attached parts is turned so that the nipple I6 is depending, and then said head I 3 is screwed onto or otherwise rigidly secured to the barrel i2, thereby 'iorcing the tapered nipple II into the open axial discharge passage of the cartridge. When the two heads are thus applied to the barrel l2 and the shank of the handle I! is screwed into the hub of the head I, as shown in Fig. 1, the outer stem section 22 will press the valve 25 tightly against the hub oi the piston head, said hub and the rod 24, and the piston head will then be moved into the cartridge shell, approximately as shown in Fig. 1. At such time, of course, the collar 2|, spring 21, will tightly seat the rim of the axial passage 9 onto the nipple II. It is important to note that the beveled edge oi the collar 28, during the above operations, served to keep the cartridge shell centered in respect to the axis of the barrel l2, thereby making entry of the piston initially into the cartridge shell an easy matter.

The above noted initial movement of the piston head into the cartridge shell served to discharge enough grease from the cartridge to fill the barrel or small cylinder 8| 01' the differential high pressure grease ejector. When the valve head 43 is pressed, valve 22 will open communication between conduits 40 and ll, and this will simultaneously admit air under pressure against the large ejector piston 32 and through the pee-'- sage 44 into the shell 82 and against the back or outer face of the piston head ih-iiil.

The spring closed valve 45 acts as a pressure reduction valve so that less air pressure per square inch will be introduced against the car- 32 of the high pressure grease ejector. The pressure against the cartridge engaged piston, however, will be sumcient to always keep the barrel 3| always filled with grease but not suihcient to In view of the very much larger area of piston 32 than of plunger 33, the grease discharged through discharge passage 53 will be under very high pressure.

After the grease has been elected from the cartridge, the followeracting piston will be with drawn from the cartridge shell. At the time that this piston reaches the head 8 oi the cartridge,

the piston stem, made up of the sections 22, 23

and 24, will be extended as far as they can go, and hence, withdrawal of the stem will retract the piston. In eflecting this return movement of the piston, the handle I! will be unscrewed from the head ll. Initial return movement of this piston from place under a partial vacuum produced in the shell. Whenever thispartial vacuum, acting on the piston against the pull on the stem, is sufficient to compress spring 2| to overcome spring 2|, valve 25 will be pulled away from the hub of the piston, thereby permitting atmospheric pressure to enter the shell, thereby making the withdrawal of the piston an easy matter.

It is now important to note that this initial return movement of the piston in moving the valve to open position, causes said valve to act m the inner end 01' the cutting or distorting dog r dogs 28, thereby forcing the outer ends of said logs against the cartridge shell so that outward novement of the piston will cause said dog to either cut or groove or otherwise distort the carridge shell so that it can not be again used as a thereby closing the air passage betweenunder the'action oi the the hub 20' moves with piston and admits air into the cartridge the cartridge shell will take large open end of said container. This cutting or distorting device will be applied when, and only when, it is desirable to prevent refilling oi the cartridge.

The valve 36 forms no part of the present invention, but it may be stated that the purpose thereof is to relieve the discharge pipe or conduit from pressure after the injection of grease so as to relieve certaintypes oi coupling nozzles to receiving nipples, and thereby rendering the disconnection oi the said elements an easy matter.

Operation of the structure illustrated in Figs. 3, 4 and 5 The operation oi the structure illustrated in Figs. 3, 4 and 5 must be quite obvious in many respects from the description of the operation of the structure illustrated in Figs. 1 and 2. However, this last noted structure being of a manually operated type. the following statements are deemed desirable: When the sleeve 41 is drawn to'an extreme outward position, its beveled end will cam the latch lever 52 into engagement with the lock groove BI and will hold said sleeve against the movement later to be imparted thereto by the spring 80.

The manner of introducing the cartridge into the grease gun and of.initially entering the follower-acting piston into the cartridge shell is very much the same as that previously described. That is, when the barrel i2 is connected to the heady it with the cartridge applied therein, the piston will be initially entered into the cartridge shell. Then, when the latch lever 52 is pressed and the sleeve 27; released, the spring 59 will force the flange end Qt] against the piston, thereby closing the air passage through the hub 20' and pressing the said piston into the cartridge shell as far as it will be permitted to go by the contents of the cartridge.

When the piston has moved to its extreme posi tion indicated by dotted lines in Fig. 3, and the piston is to be retracted, handle 81' will be pulled out of the head M, and the then extended piston stem will be caused to pull the piston backward and out of the cartridge shell. Initial backward pull on the piston stem, in addition to retracting the piston, performs two operations, to

wit: It causes the cutting dogs 28 to engage and distort the cartridge shell, and initial movement of said stem permitted by the recess in flange 69 out of engagement shell, thereby relieving theaction of partial vacuum which would otherwise resist the retraction of the'piston.

The operation of the high pressure grease ejector involving the plunger acting stern Ii is, of course, perfectly obvious.

What I claim is: t

1. In a grease gun structure, a barrel-like casing, a front head to which said barrel is secured, said head having an axial discharge passage, a rear head for said barrel, a grease-containing cartridge having at one end an axial discharge passage adapted to form a fluid tight joint with the axial discharge passage of said front end, said cartridge having a full a piston head adapted diameter open rear end,

for insertion into said grease cartridge, means for yieldingly pressing said piston head into said grease cartridge and means for retracting the same, and a yieldingly pressed collar substantially fitting said casing and engageable with the rim of the open end of said grease cartridge to seat the same.

the grease container in respect to said piston head.

4. The structure defined in claim 1 in which the means for retracting said piston head includes an element on which said piston is mounted for limited sliding movements, and a distorting dog pivoted to'said piston head and subject to initial retracting movement of said retracting means to movev said dog against the wall of the grease container and cause distortion thereof under the retracting movement of the piston head.

5. In a grease gun structure, a barrel-like casing,'a front head to which said barrel is detachably secured, said front head having a grease discharge passage, a rear head secured to said barrel; grease-containing cartridge having at one end an axial passage adapted to form a fluid tight joint with the axial discharge passage of said front head, said cartridge having the full diameter open rear end, a piston head adapted for insertion into the large open end of said caryieldingly pressing said piston tridge, means for head into said cartridge, and a retracting plunger working through the rear head of said casing and connected to said piston head, said casing when removed from said front head being adapted to receive the grease-containing. cartridge therein while said piston head remains within said container and attached to its operating means, and yielding pressure device reacting against said outer head and operative on the outer rim of said cartridge to seat thesame against the front head. a

6. In a grease gun structure, abarrel-like casing, a front head to which said barrel is detachably secured, said front head having a grease discharge passage, a rear head secured to said barrel, a grease-containing cartridge having at one end an axial passage adapted to form a fluid tight joint with the axial discharge passage of said front head,said cartridge having the full diameter open rear end, a piston head adapted for insertion into the large open end of said cartridge, means for yieldingly pressing said piston head into said cartridge, and a retracting plunger working through the rear head of said casing and connected to said piston head, said casing when removed from said front head being adapted to receive the grease-containing cartridge therein while said piston headremalns within said container and attached to its operating means, in'

further combination with a spring-pressed collar substantially fitting said casing andoperative on the large open end of said cartridge to hold the same seated.

'1. In a'grease gun structure, a barrel-like casing,a front head to which said barrel is detachably secured, said front head having a grease discharge passag'e, a rear head secured to said barrel, a grease-containing cartridge having at one end an axial passage'adapted to form a fluid tight joint with the axial discharge passage of said front head, said cartridge having the full diameter open rear end, a piston head adapted for insertion into the large open end of said cartridge, means for yieldingly pressing said piston head into said cartridge, and er working through the rear a retracting plung head of said casing said container and attached. to its operating means, said piston head being capable of, slight axial movements in respect to its retracting plunger, and in further combination with a distorting dog pivoted-to said piston head and rendered active by initial piston retracting movements of said plunger to cause distortion of the walls of the cartridge under continued retracting movement of said piston head.

8. In a grease gun structure, a barrel-like casing, a front head-to which said barrel is detachably secured, said front head having a grease discharge passage,-a rear head secured to said barrel, a grease-containing cartridge having at one end an axial passage adapted to form a fluid tight joint with the axial discharge passage of said front head, said cartridge having the full diameter open rear end, a piston head adapted for insertion into the large open end of said cartridge, means for yieldingly pressing said piston head into said cartridge, and a retracting plunger working through the rear head of said casing and connected to said piston head, said casing when removed from'said front head being adapted to receive the grease-containing cartridge therein while said piston head remains within said container and attached to its operating means, in further combination with means operative on said retracting plunger to lock said piston head in a retracted position.

9. In a grease gun structure, a barrel-like container, a front head to which said barrel is detachably secured, said head having an axial discharge passage, a rear head for said barrel, an ejecting plunger mounted on said rear head and having means for projecting and retracting the same axially of said barrel, and a grease-containing cartridge having at one end an axial discharge passage adapted to form a fluid tight joint with the axial discharge passage of said front end, said cartridge having a full diameter open' rear end into which said ejecting piston is insertable, in further combination with the springpressed collar spring connected to said rear head and engageable with the large end of said cartridge to seat the discharge passage of the latter against the discharge passage cf said front head, said collar having a beveled front edge for centering the cartridge shell in respect to said ejecting plunger.

, 10. In a greasegun structure, a barrel-like casing, a front head to which said barrel is secured, said head having an axial discharge passage, 2. rear head for said barrel, a grease-containing cartridge having at one end an axial discharge passage adapted to form a fiuidtight joint with the axial discharge passage of said front end, said cartridge having a full diameter open rear end, a piston head adapted for insertion into said large open end of said grease cartridge, means for yieldingly pressing said piston head into said grease cartridge and means for retracting the same, and. a yieldingly pressed collar substantially fitting said casing and engageable with the rim of the open end of said grease cartridge to seat the'same.

11. In a dispensing gun for plastic material, a barrel-like casing including front and rear head members, the front head member having a discharge passage, one of the head members being detachable from .the barrel, a cartridge for plastic material adapted to be removably disposed in the casing when such head member is detached, said cartridge haying a discharge passage adapted to form a fluid-ti' ht joint with the discharge passage or the front" ead member when the cartridge 'is moved'iendwisetoward the front head, the end of the cartridge opposite the discharge passage being open, plunger means extending from the rear head member and adapted to en-- ter the open end 01' the cartridge to express the contents therefrom, and a spring pressed. member movably carried by the casing and which yieldingly engages therim oi the open end of the cartridge when the detachable head member is in place on the casing, so that the spring pressed member exerts pressure through the cartridge in a manner tending to maintain said fluid-tight joint.

12. The arrangement according to claim 11 wherein the spring pressed member is of annular form for continuous engagement with the rim of the cartridge, and has a snring behind it which reacts against the rear head member the cartridge toward the front head member.

s'rnvan J. max. 

